William Stein wrote: > On Fri, Apr 11, 2008 at 10:43 AM, Ryan Hinton <[EMAIL PROTECTED]> wrote: >> Sorry, I meant to. One problem is that the Sage pre-parsing results >> in different behavior than I am seeing, so pasting code into a Sage >> session will not exhibit the problem I am seeing. > > Include > > sage: preparse(False) > > at the top of the example to turn off the Sage preparser. > Alternatively, you can do Integer=int; RealNumber=float > to turn off just bits of it. > > It looks like below the issue is that you want to use > the Python builtin round instead of Sage's round. > That Sage uses it's round instead the builtin one > by default has nothing to do with the preparse. It's > just because we import our own round in > > from sage.all import * > > We do that because the semantics of Python's builtin > round aren't optimal for Sage. >
Ryan, If you use Sage's round command: from sage.all import round or from sage.misc.functional import round then the example seems to work just fine: sage: vector([round(frac*length) for frac in fracs_list]) (5, 3, 2) If I wanted to be sure that I had an integer vector, I could specify the parent explicitly, just like with matrices: sage: vector(ZZ,[round(frac*length) for frac in fracs_list]) (5, 3, 2) That said, William, is there a reason why this doesn't work? This is what is necessitating the two type conversions above. sage: Integer(float(2)) --------------------------------------------------------------------------- <type 'exceptions.TypeError'> Traceback (most recent call last) /home/grout/<ipython console> in <module>() /home/grout/integer.pyx in sage.rings.integer.Integer.__init__() <type 'exceptions.TypeError'>: unable to coerce element to an integer sage: Integer(RDF(2)) --------------------------------------------------------------------------- <type 'exceptions.TypeError'> Traceback (most recent call last) /home/grout/<ipython console> in <module>() /home/grout/integer.pyx in sage.rings.integer.Integer.__init__() <type 'exceptions.TypeError'>: unable to coerce element to an integer I guess I would think it was a design decision to not convert floating points to ints automatically. However, the following does work: sage: Integer(RR(2)) 2 This seems inconsistent. Jason --~--~---------~--~----~------------~-------~--~----~ To post to this group, send email to sage-support@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/sage-support URLs: http://www.sagemath.org -~----------~----~----~----~------~----~------~--~---
